568-219 BUNA 70 SQUARE CUT RINGS

APG stocks the SH70219, an AS568-219 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring built to an inside diameter of 1.296 in (32.92 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.574 in (39.98 mm). A square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.

As a material, Buna-N (Nitrile) is known for strong abrasion and tear resistance, low compression set under sustained load. The material holds up against many alcohols, petroleum-based oils, and greases and lubricants. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or ketones call for a different compound. The profile itself contributes simple lathe-cut manufacture at low tooling cost and a rectangular section that will not roll in the groove. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.

You will find this material specified across general industrial maintenance, automotive, and hydraulic and pneumatic systems.

This item is sold individually under part number SH70219. Unit weight is approximately 1.6448 g and nominal inside diameter is listed as 1 5/16 inch. Review your operating media and conditions against this specification before installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.